[ticket/11556] Remove fallback JS

PHPBB3-11556
[ticket/11556] Load apply_onkeypress_event() correctly

PHPBB3-11556
Merge remote-tracking branch 'remotes/cyberalien/ticket/11556' into develop

# By Vjacheslav Trushkin
# Via Vjacheslav Trushkin
* remotes/cyberalien/ticket/11556:
  [ticket/11556] Load apply_onkeypress_event() correctly
  [ticket/11556] Remove fallback JS